First off, why aren't there more recent posts on here. Most, esp. for BK 5.2G is from 2007 and is about running on Windows Vista. Only rare mention of Windows 7.
I am running BK 5.2G under Windows 7 Home Premium 32-bit. There are some issues (it doesn't display any changed info right away and have to go to someone else and then back to see changes) but otherwise runs well.
Note that I said 32-bit. I was fortunate to buy my laptop when Win 7 was new and mostly coming in the 32-bit variety.
Windows (or Vista or XP) 64-bit will NOT run DOS or Win 3.1 era programs natively, i.e you'd have to install an XP or other emulator to run the app under it.